Automatic alarm mechanism



Aug. l0 1926. 1,595,598

J. S. BRENNAN AUTOMATIC ALARM MECHANISM Filed May 29 1925 Patentedy Aug. l0, 1926.

PATENT orales.

JAMES s. ora'rrLEBono, MASSACHUSETTS.

AUTOMATIC Lama MECHANISM.

Application alestra# 29, 1925; serial No. 33,693.

`This invention relates to an automatic alarm'mechanism adaptedI for use incennection with an electricbell to indicate fires or the overheatingk of furnaces, chimneys or other parts of heating equipment liable to overheat and cause fires in'dwelling houses',

factories and the like, aswell as 'in indicatiingthe overheating of machine parts.l

ne object of the invention is the 'proviL sionloff a structure of the character described wherein a readilyfusible metal clip isernployed to hold electric contacts outof engagement,.such clips being renewable'y after each ,operation of the alarm-y mechanism thereby making it unnecessary for the user to either provide a new alarm mechanism or resolderthe fusible conneetionlafter eachoperation as is the case with the structuies now in use. Y

A further object 'off the invention is to provide a device of this character`r adapted to be suspended in anyv desired positiorrel'a'- tivetothe heating equipment, anidl faraon-y strncted aslto occupy litt espcewherebyit ma be sofi placedr as to beout' ofthe-way" an' not liable'to be"disturbedbythe'ope'raitionI ofi the heating apparatus;

Another object `ofthe"invention istheprj vision of an improved'eircuit closing mech-fkr anisfn4 of the character described' and pro,-

vided* with plated' centaet points Mwhereby'f ered4` IorL the same* rendered inoperative 'thrugh the fornaticnof nonlconductig metallic compounds thereon;

Otherobjects andadvaltagesioff the in` ventibn relate to' certain? Iimproved` tdetails ofcofnstruetion, asfwell as certain novel methods of operation as vwill be fnior'e fully set" forth: in; the low.

Referring to lthe accompanying draw-` ings Fig. lv is a perspective view ofthe struc-v Fig'.v A3 is a verticwlsecteiial-view of the structure, takenalong'tleliie'B--Bfof fig: 2.1/ Fig. 4 is an'enlarg'e perspective fvlew of detailed description to' folfront elevational view' ofthey the clipprovided witha fusible connection for releasing the circuit closing'tongue, and, Fig. 5 is anfenlarged sectional view taken alog the line5--5 of Fig. 2 and showing one of' the insulating` elements in detail.

In the embodiment of the invention illustrated herewith l designates gener-ally the alarm mechanism which comprises two metallic plates 2 andv 3 which are spaced fromv each other by twofor more spacin washers 4 of insulating lmaterial and! secure together by suitable fastening means such as screws or rivets 5 passedy through the registering' openings 6 yin the plates2 and 3 and suitable openings 7 in the' spacing washers.

The openings in one of the spacedplates, in the presentcase the rear plate 2, are formed of suflicient sizey to receive they ref duced ends 8 of the spacing washersfliwheref byffthe' rear' plate may be suitably insulated fromv the 'fastening' means 5, and relativr-rlyy thin' washers 9 of insulating material may be placed'k between. the# oppositel sidek of the rear' plate-2 andthe head-10pt each fastener' 5 to insure that the rear plate 2 will be completely insulatedfrom the front plate 3. `v

Ani opening 12 is formed in' the front plat'ev-of sufficient sizeto' give access to a portionr ofthe rear late 2 for al purposel which will be more-fu ly setforth. The rear plate 2 is provided with converging slots 13 terminating ina arc-shaped opening.v 14,-the entf-'away portions of the ymetal being so shaped as to leave a taperedtongue'l which is Iintegralwith the rear plate 2. The metal plate 2 is preferably formedt of-resilient material whereby thei'tongue 15 Ama be bent to incline towards and have its tip' contact with the inner surface of the front plate 3, when'the tongue l5 is notk restrained by some suitable means. f

Aclip l7`is provided which may be of cireulariform or of such 'other suitablev shapey as may bedes-ired,l the clip 17 being of suiiicient sizef ynot to pass readily through the arcshapedopeningli, and a metalfstripfflSlis soldered upon one face of the clip 17 by Ineans of; solder so 'constituted as to melt at the desired temperature. The metal strip 18l' may be bowed slightly sothat whenlsecured to the clip 17 it willprovide an eye- 19 for the reception ofthe narrowedl endof theV ton ue 15.'-

In assembling the alarm mechanismfor use, the operator may have access to the Uil tongue 15 through the opening 12 in the front plate to force the tongue 15 backwardly until the end of the tongue may be inserted in the eye 19 formed by the strip 18, whereupon the clip 17 may be permitted to engage the rear plate as `shown in Figs. 2 and 3 of the drawings, the tongue 15 being thereby held from contact with the front plate and the plates 2 and being insulated from each other. The strip 18 is of less length than the diameter of the arcshaped opening lelwhereby when the solder Q connecting the strip 1S to the clip 17 melts the strip 1S will no longer hold the tongue 15, the end of which will 'spring forward and engage the inner surface of the front plate to thereby close the circuit to the electric bell.

A metal lip 22 is struck out from the front plate 3 and a similar lip is struck out from the rear plate 2 which serve as means for connecting wires 2l and 25 to the front and rear plates respectively, the said wires being connected respectively to one terminal of an electric battery 2G and one terminal 27 of an electric bell 2S, the terminal Q9 of the electric bell 28 being connected with the other terminal of the battery 2-1 by means of the wire 30.

A. support 32 may be formed integral with one of trie plates or suitably secured thereto as may be found desirable in practice and provided with an opening 33 by which the plates may be suspended from any suitable hanger Si if desired.

The end portion of the tongue which contacts with the inner surface of the front plate 3 at approximately the point 35, when the tongue 15 is released by the melting of the solder 20, may be plated or washed with any suitable metal as well as that part of the inner surface of the front plate 3 with which the end of the tongue 15 contacts, whereby the failure of the device to act to close the circuit by reason of the formation of nonconducting material on the end of the tongue or the inner surface of the front plate will be obviated.

1n the operation of the mechanism, the tongue 15 may be reached through the opening 12 in the front plate and pressed back a sufficient distance so that the end of the tongue 15 may be inserted in the eye 19 as shown in Fig. 2, whereupon the tongue may be released to permit the clip 1T to bear against the outer surface of the rear plate 2 as shown in Figs. 2 and 3 of the drawings, llfhen the temperature reaches a point sufficient to melt the solder 20, the metal Istrip 18 will be released from trie clip 17 and free the end of the tongue 2O which will move to the dotted line position shown in 3 and engage the front plate 3 to close the circuit and cause the ringing of the bell 28.

lhen it is desired to reset the mechanism a new clip 17 may be employed, thus by making the fusible connection on the clip 1'? and separate from the rest of the mechanism, a plurality of clips may be kept ready for use and the necessity for resoldering the fusible connection after each operation of the mechanism avoided.

lVhile I have shown and described the above mechanism in connection with the usual type of electric bell for producing an audible alarm I am aware that it may be utilized for a variety of purposes such as for closing an electric circuit to operate an indicator' or to actuate a control, and therefore I do not intend to be limited to the use of the same in the precise relationship with associated mechanism as illustrated herewith but propose in the appended claims to cover the circuit closer mechanism broadly regardless of the particular use to which it may be applied.

lVhat I claim is 1. An automatic alarm mechanism comprising a pair of oppositely positioned spaced metallic elements insulated from each other, one of said elements being provided with a spring tongue normally movable into contact with the other element, said last named element being provided with an opening for permitting access to the spring tongue, and a separable clip engagiiw said lirst named element and having a fusible connection for holding said tongue out of engagement with said second named element, said fusible connection releasing said tongue to permit the same to contact with said second named element when the temperature reaches a predetermined point.

An automatic alarm mechanism comprising a pair of oppositely positioned spaced metallic elements insulated from each other, one of said elements being provided with an integral spring tongue normally movable into contact with the other element and having a portion thereof cut away adjacent to the free end of said tongue, and a separable renewable holding member independent of said metallic element contacting with the edges of the cut away portion of said first element and having a fusible connection for holding said tongue out of engagement with said second named element, said fusible connection being adapted to release said tongue to permit the same to contact with said last named element when the temperature reaches a predetermined point.

3. An automatic circuit closer for an electric circuit comprising a pair of spaced metallic elements insulated from each other and secured together, one of said elements having a portion struck out therefrom and normally movable into contact with the other of said elements to close the electric circuit and provided with an enlarged open ing adjacent to the free end of said struck out portion, and a renewable clip engaging said first named element adjacent to said opening and having a fusible connection for holding the movable portion of said first named element out of contact with said second named element but adapted to release said movable portion to permit the same to contact with said second named element when the temperatures reaches a predetermined point.

4. An automatic circuit closer for an electric circuit comprising a. air of spaced metallic elements insu-lated flfom each other, a spring tongue integral with one of said element-s and normally movable into contact with the other of said elements to close the electric circuit, and a clip having a portion engageable with said first-named element and provided with a fusible connection adapted to engage the spring tongue and retain the same substantially in-the plane of said first named element and out of contact with said last named element until the temperature reaches a predetermined point, the fusible connection being adapted to release said tongue to permit the same to move out of the plane of said first named element and to contact with said last named element when the temperature reaches a predetermined point.

5. An automatic alarm mechanism comprising a pair of oppositely positioned metallic plates secured together in spaced parallel relation and insulated from each other, one of said plates being provided with an integral spring tongue and having an enlarged opening adjacent to the free end of said spring tongue, the said spring tongue being adapted to engage the second of said plates to close an electric circuit, and a renewable clip member provided with a body portion adapted to engage the said iirst named plate adjacent to the enlarged opening therein and provided With a fusible connection engaging the said tongue for holding the tongue out of contact with the said second element, the fusible connection being releasable when the temperature has reached a predetermined point to permit the free end of said tongue to contact with said second element and close the electric circuit.

In testimony whereof I have affixed my signature.

JAMES S. BRENNAN. 

